A device configured to detect a moving substance with an infrared ray camera, estimate the position of the moving substance from the amount of movement and the direction of movement thereof in a short time and irradiate a laser beam, a device configured to detect an area of movement by acquiring a difference of images and fan the area of movement, and a device configured to take images of an object to be monitored, detect the position of the center of gravity of the object to be monitored from the images, and track the movement of the position of the center of gravity are proposed.
However, in the devices of the related art, if a tracking device having a low response performance is used, there is a problem that the tracking movement cannot keep up with that of the object to be monitored which moves at a high speed at a short distance.